• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.577-583
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• 2001

The digestive enzyme activities such as $\alpha-amylase$, trypsin and pepsin from the laboratory-reared river puffer Takifugu obscurus were measured from the time course of 1 day until the 65 day after hatching. In the case of $\alpha-amylase$, it was showed minimum activity of 0.0493 U/mg at the total length (TL) 10 mm, and showed maximum activity of 0.1480 U/mg at 19 mmTL. Trypsin and pepsin were showed their maximum activities of 0.0264, 0.0258 U/mg and 0.0178, 0.0201 U/mg when the total length of 16 and 24 mm, and represented remarkable correlations between the changes of enzyme activity and growth rate. The ontogenetic variations of digestive enzymes were represented clearly different patterns; i.e, the pepsin showed higher activity when the periods of larva ($4\~5\;mmTL$) and juvenile II ($19\~24\;mmTL$), however, the trypsin represented maximum activity at the stages of juvenile I ($11\~16\;mmTL$) and young fish (27 mmTL), respectively.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.3
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• pp.718-724
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• 2015

To survey the most feeding frequence of formulated diet as food for cultured puffer in winter season, we performed a rearing test using juveniles of river puffer, Takifugu obscurus (body weight 15.0 g) for 120 days. The feeding frequencies were set up as 2times/1day, 2times/2days, 2times/3days and 2times/4days. We tested triplicately the experiment and investigated survival rate, daily food intake (DFI), feed efficiency (FE), condition factor (CF), daily growth rate (DGR). Consequently, growth was increased following to an increasing of feeding frequency, was the fast in 2times/1day of feeding frequency, and was the slowest in 2times/4days (p<0.05). DFI and CF were increased following to an decreasing of feeding frequency and was the highest in 2times/4days of feeding frequency. FE was decreased following to an decreasing of feeding frequency, and was the highest in 2times/1day of feeding frequency. In a proximate carcass composition at the final day, moisture and crude lipid contents were the lowest in 2times/4days, and in survival, there was not any significant difference among experimental groups. Therefore, we concluded that the 2times/2days are the best of feeding frequency for economical benefit of river puffer culture in winter season.

• Journal of fish pathology
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• v.31 no.2
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• pp.87-92
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• 2018

A case of disease was occurred in tiger puffer, Takifugu rubripes, reared in circulated system (water temperature was about $20^{\circ}C$) on land in Korea. Diseased fish showed a unique external sign, the cloudy skin ulcer in various sizes. We investigated the cause of disease, and isolated one pure cultured bacterium, TP01. This had 99.7% homology with Vibrio atlanticus by sequence analysis of the 16S rRNA and rpoA genes. TP01 showed some differences with other reported V. atlanticus strains in the biochemical characteristics as like Voges-Proskauer test and gelatin hydrolysis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.141-144
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• 1995

The pufferfish Takifugu vermicularis radiatus (Gukmeri-bog) was examined for toxicity. Thirty-one specimens, which had obtained from creeks of Inchon and Ansan in Spring and Autumn of 1992 and 1993, Korea, were assayed for anatomical distribution of toxicity by mouse bioassay method. Ovary, testis, liver and muscle showed very strong toxicity, and intestine and skin did moderate toxicity. Their average toxicities were moderately toxic in all. Moreover, the toxicities of liver and intestine were stronger in Spring than Autumn. Judging from the results, T. vermicularis radiatus is considered to be very harmful fish. Consequently, it is necessary to take a proper preventive step against food poisoning by pufferlish ingestion.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.137-140
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• 1995

The pufferfish Takifugu obscurus (hwang-bok) was examined for toxicity. Forty-six specimens, which had Gaught at the Imjin River in 1992 and 1993, Korea, were collected and assayed for anatomical distribution of toxicity by the mouse assay method. Ovary and liver showed very strong toxicity, testis, intestine, gall bladder and spleen did moderate toxicity, muscles and skin did weak toxicity, and blood was non-toxic. The results of this study were different from those of Tani, who had examined the toxicity in 19 species of pufferfish, in terms of toxicity in testis, muscle, and skin. The toxicity of testis and muscle had been known to be non-toxic or weakly toxic previously, however, they were known to have weak or moderate toxicity. Therefore, careful attention should be taken to prevent food poisoning by pufferfish ingestion.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.383-389
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• 2014

An 8-week feeding trial was conducted to determine the apparent dry matter and protein digestibility of seven different dietary protein sources by juvenile river puffer Takifugu obscurus. Eight diets containing white fish meal (WFM), brown fish meal (BFM), squid liver powder (SLP), krill meal (KM), leather meal (LM), soybean meal (SM), or fermented soybean meal (FSM) were prepared by mixing a basal diet (BD) with one of the seven test ingredients at a ratio of 7 to 3. Fish averaging $10.8{\pm}0.04g$ were fed the experimental diets in triplicate groups. The apparent dry matter digestibilities of BFM, WFM, FSM, SLP, LM, SM, and KM were 80, 78, 72, 67, 56, 55, and 54%, respectively, while the corresponding apparent protein digestibilities were 96, 96, 93, 92, 89, 88, and 86. The weight gain of fish fed BFM was significantly greater than that of fish fed SM or LM (P<0.05), while it was not significantly different from that of fish fed the BD, WFM, FSM, BFM, SLP, or KM. These results indicated that WFM, BFM, FSM, and SLP are potentially good protein sources for replacing fish meal in river puffer feed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.3
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• pp.175-178
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• 2004

We here report that the muscle of 'gukmeri-bok' puffer fish (Takifugu vermicularis radiatus) is intoxicated after freezing and thawing processes even though it is not toxic when it is fresh. This study was carried out to investigate the effect of different freezing and thawing conditions as well as the effect of the presence of skin or viscera on the intoxication of muscle of 'gukmeri-bok' puffer during freezing and thawing process. As a result of this investigation, thawing condition, but not freezing conditions or periods played an important role in muscle intoxication. Tetrodotoxin secretory grands exist in the skin of toxic puffer fish, the skin was more responsible for the muscles intoxication than the viscera during the freezing-thawing process. In other words, no toxicity was measured in the muscle of skinned-frozen specimens even when thawed. According to this result, it is recommended that the skin and viscera must be removed before being frozen for edible purpose. Otherwise, when a whole fish should be frozen, alternative half-thawing and removal of skin from frozen specimens is recommended.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.124-128
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• 2021

This study was conducted to evaluate the effects of incubation methods and transfer timings on the hatching rate of fertilized eggs of the river puffer Takifugu obscurus. Four incubation methods were tested, a) control (fertilized eggs attached to the glass plate), b) bottom (fertilized eggs spread on the bottom of the tank without any treatment), c) S-bottom (removing the stickiness of the fertilized eggs, and then spreading the eggs on the bottom of the tank), and d) incubator (removing the stickiness of the fertilized eggs, and then incubating the eggs in an incubator). Additionally, four transfer timings were tested: a) control (no transfer from the incubation tank), b) zygote (fertilized eggs transferred at the zygote stage), c) segmentation (fertilized eggs transferred at the segmentation stage), and d) pharygula (fertilized eggs transferred at the pharygula state). The results showed that the hatching rate of incubator was significantly higher than those of control, bottom, and glass (P<0.05). The results also showed that the hatching rates of control and pharygula were significantly higher than those of zygote and segmentation (P<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.878-885
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• 2020

Previously, we reported that globefish Takifugu obscurus homogenate suppresses the growth of human colorectal cancer cells. To extend the applications of globefish homogenate, we investigated its cytotoxic effects on human breast cancer cells. To assess the effects of globefish homogenate on growth of MCF (Michigan Cancer Foundation)-7 human breast cancer cells, cell proliferation and colony formation assays were performed using the cell counting and Crystal Violet staining methods. The 50% inhibitory concentration (IC50) of globefish homogenate on MCF-7 cell proliferation was calculated from the sigmoidal dose-response curve. The colony formation assay demonstrated that MCF-7 cells treated with globefish homogenate formed up to 80% fewer colonies than control MCF-7 cells. Treatment with globefish homogenate markedly suppressed the growth of MCF-7 cells in a dose-dependent manner. The sensitivity of the cells to globefish homogenate was determined by calculating the IC50; in this case, the IC50 was 210 ㎍/mL. Furthermore, significant downregulation of Cyclin D1 expression, along with phospho-Akt and total Akt levels, was observed in MCF-7 cells treated with globefish homogenate. This study demonstrates that treatment with globefish homogenate inhibits the proliferation of MCF-7 human breast cancer cells by downregulating the expression of phosphor-Akt, total Akt, and Cyclin D1 proteins.

• Journal of Life Science
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• v.14 no.3
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• pp.417-424
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• 2004

This study attempts to investigate lectin binding patterns of the glycoconjugates of the esophageal mucous cells in four teleostean speceis, i. e., Sebastes schlegeli, Halichoeres poecilopterus, Bryzoichthys lysimus and Takifugu pardalis. To investigate glycoconjugates of esophageal mucous cells, nine biotinylated lectins (DBA, SBA, PNA, BSL-l, RCA-l, sWGA, UEA-l, LCA and ConA) were applied with ABC method. Esophageal mucous cells of Sebastes schlegeli and Halichoeres poecilopterus were mixed with large, medium sized and small mucous cells. But these cells of the other species only were mixed with medium sized and small mucous cells. The lectin binding pattern of esophageal mucous cells depends on the species; Sebastes schlegeli was stained with DBA, SBA, BSL-l, RCA-l and sWGA, Halichoeres poecilopterus with DBA, SBA, PNA and sWGA, Bryzoichthys lysimus with SBA and sWGA, Takifugu pardalis with all lectins except DBA, LCA and Con A, respectively. All the mucous cells of Sebastes schlegeli were stained with DBA, SBA and sWGA, while small mucous cells with BSL-l besides these lectins. In Halichoeres poecilopterus,l the large mucous cells reacted with PNA, medium sized mucous cells with DBA, SBA and sWGA, and small mucous cells with DBA and SBA, respectively. Medium sized mucous cells of Bryzoichthys lysimus were stained with sWGA, and small mucous cells with SBA and sWGA. In Takifugu pardalis, all mucous cells reacted with SBA, PNA and RCA-l, but medium sized mucous cells with sWGA and UEA-l besides these lectins. Especially DBA and SBA lectins showed a strong binding to all mucous cells of Sebastes schlegeli. In Halichoeres poecilopterus, PNA binding were notable in large mucous cells, and SBA binding in medium sized and small cells, respectively. However, SBA, PNA, sWGA and UEA-l lectins of Takifugu pardalis showed a strong binding to medium sized mucous cells, but RCA-l binding which small mucous cells were notable.